Vehicles for steam-set printing inks



Patented May 21, 1946 2,400,519 .VEHICLES FOR STEAM-SET PRINTING INKS John W. Kroeger, Drexel Hill Plaza, and Daniel J. O'Connor, Jr., Yeadon, Pa.,

assignors to Fredk H. Levey (20., Inc., New York, N. Y., a corporation of New York v No Drawing. Application July 26, 1944, Serial No. 546,739

4 Claims.

This invention relates to vehicles for printing inks of the quick-drying type, in particular those inks which are dried quickly by application of steam to the freshly printed web or sheet thereby giving prints which are rub-proof and which will not offset when rewound or stacked.

Vehicles for use in the manufacture of such ,inks have been made up of a water-insoluble resin dissolved in awater-soluble solvent. Inks consisting of pigments suspended in such vehicles are converted to dry films by the action of steam which causes water. to dissolve in the film thereby precipitating the water-insoluble resin. These inks suifer from the very serious difliculty that at high relative humidities, such as may be encountered in summer weather, the inks dry pre maturely on inking rollers and printing plates due to precipitation of the resins by the high moisture-content of the surrounding air.

It has been found that inks containing watersoluble resins instead of water insoluble resins will dry quickly upon application of steam even though no precipitation of the resin occurs. Suchinks are described in the co-pending application of Kroeger and OConnor, Serial No. 466,672, filed November 23, 1942.

An object of this invention is the improvement of vehicles for steam-setting inks which are not set on printing rollers and plates even by-atmospheres of 100% relative humidity.

A further object of this invention is the preparation of such vehicles from very low-cost materials.

Another object is the development of such vehicles in which the resins are not susceptible to conversion to an insoluble form by the action of certain active pigments.

Another object is the development of such vehicles which are not highly acid and hence do not cause foaming with certain pigments containing carbonates.

Another object of the invention is the preparapigments. They are soluble in water hence inks prepared from them are unaffected by high humidities and since their solutions are slightly alkaline, acid-sensitive pigments can be used. In addition, we have found that ink films containing such salts become insoluble in water within 24 to 48 hours after printing. This phenomenon may be due to an irreversible dehydration which has been noted with certain types of emulsifying agents whereby films containing such agents are no longer capable of being redispersed in water after aging for 24 to 48 hours.

In pure form these salts are resinous materials resembling in appearance the resins from which they were made. They can be prepared by (1) reacting the amine with the resin followed by solution in a liquid polyglycol, (2) by addition tion of vehicles which will give water-resistant ink films within 24 to 48 hours after printing.

Other objects and advantages of the invention will be apparent as it is better understood by reference to the following specification in which the preferred embodiments are described.

We have discovered that vehicles with the desired properties of water-miscibility, with consequent lack of susceptibility to humidities of even 100%, and low acidity, can be obtained by preparing solutionsof certain amine salts of rosins in a liquid polyglycol. These salts have resinous propertie in that they are excellent binders for of the amine to a solution of a resin in a liquid polyglycol or (3) by dissolving the resin in a liquid polyglycol containing the amine. change in the character-of the resin is quite striking. Solutions of many of the resins in diethylene glycol have almost no tolerance for water and on exposure of the surface of the solution to normally humid air an opaque film of precipitated resin immediately flashes acrossthe exposed area. After conversion to an amine salt not only is this behavior eliminated but the solution can be diluted indefinitely with water. Varnishes made with these salts have unusually good wetting properties for many types of pigments due to the strongly polar nature of the binder molecule.

Suitable amines for the preparation of the substituted ammonium salts described above are mono-, di-, and tri-ethanolamines, mono-, di-,

and tri-propanolamines, the butanolamines, ethylene diamine, diethylene triamine, triethylene tetramine, propylene diamine, morpholine, morphoiino-ethanol, piperazine and hydroxyethyl ethylene diamine. The resins used in the preparation of the salts advantageously have an acid number between and 305.

As mentioned previously inks containing such salts as binders for the pigments have the very desirable property of remaining water-miscible indefinitely in bulk yet when printed the films become water-resistant in 24 to 48 hours. In some cases resistance to water may be attained in as little as 8 to 12 hours or even instantaneously.

Complete salt formation is obtained when exactly one equivalent of amine is used for each equivalent of the resin. Howeventhis invention should not be construed as being limited to these proportions. In many cases good results are ob- The- Example 1 Parts Rosin, acid number: 120.6 55.5 Diethylene glycol 37.3 Triethanolamine 13.3

This proportion of triethanolamine corresponds to 0.75 equivalent per equivalent of rosin.

The three materials were mixed and heated to 140160 C., until the solution was clear. The product was a moderately tacky varnish with good length and flowand was miscible with water. A 25% solution in distilled water had a pH of 8.2.

Example 2 Parts Rosin, acid number: 120.6 55.0 Diethylene glycol 37.3

Triethanolamine (1.0 eq. per eq. of rosin) 17.8

The rosin and diethylene glycol were mixed and heated to 149 C. until the solution was clear.

. After cooling the triethanolamine was added and the solution was again heated to 93 C. The product was miscible with water and a 25% solution had a pH of 8.4.

Inks are prepared by pigmenting as desired.

Example 3 Parts Rosin, acid number: 120.6 55.50 Diethylene glycol 37.30 Morpholine (1.0 eq. per eq. of rosin) l- 10.35

The procedure described in Example 2 was used. 1

The product was miscible with water and a 25% solution had a pH of 9.18.

Example 4 Parts Rosin, acid number: 120.6 55.5 Diethylene glycol 37.3 Morpholine (0.75 eq. per eq. of rosin) 7.8

Th procedure described in Example 2 was used.

The product was miscible with Water and a 25% solution had a pH 01.9.11.

Example 5 Parts Rosin, acid number: 120.6 55.5 Diethylene glycol 37.3

2-ethyl-2-amino-1,3-propandi0l (1.0 eq. per

eq. of rosin) 14.2

The procedure described in Example 2 was followed. The product was miscible with water Example 6 Parts Rosin, acid number: 50.0 Diethylene glycol 50.0 -Triethanolamine (0.51 eq. per. eq. of rosin)- 10.0

Dispersing agent (non-ionic. high molecular weight, poly-ether-alcohol) 5.0

The procedure described in Example 1 was used.

The product was miscible with water.

Other examples are tabulated below:

Table I In each of the examples below 56.0 parts of rosin (acid number:

Table II In each of the examples below 50.0 parts of rosin (acid number: 145) and 40 parts of di ethylene glycol were used.

a Eq. per Parts pH 57 hxample Ammo eq. rosin amine Sol. 0

'Iriethanolamine 0. 8 15. 5 8. 00 Tetraethylene-pentaminc 1 8.0 39. 2 9. 87 Monoethanolamine l. 0 7. 9 8. 50

. Eq. per Parts pH 5% Example Amine eq.shellac amine solution 12. Monoethanolamine 1.0 2.85 8.20 13; Triethanolam1ne. 1:0 6. 95 7. 49 1L -.c Trieth'anolamine 0. 8 g 5. 56 7. 01 l5. Piperazlne hexahydrate... 2.2 9. 98 9. I0 16 2-amino-2-ethyl-l,3-pro- 1.0 6 55 7. 78

pandiol. l7 Ethylene diamine 3.0 5.00 I 0.02

The varnish of Example 17 gave a cloudy dispersion when diluted with water.

Examples involving Other resins are listed in Table IV. The resin of Example 20 was prepared from rosin and fumaric acid by the diene synthesis and had a softening point of 229 F. The resin of Example 21 was prepared from 92 parts of glycerol, 116 parts of fumaric acid and parts of rosin by heating at 200 C. for 45 minutes. The resin of Example 22 was prepared from 92 parts of glycerol, 166 parts or phthalic acid and 160 parts of resin by heating and a 25% Solut o had 2 DH of 9.26. 65 at 200 C. for 1.75 hours.

Table IV Acid Parts d' e tl ig l Parts 1 m n 7 r no ap 5 Example Resin ig 3 resin ene nolamine SOIHUOfI glycol Gum mastic" 62. 2 50 50 16.6 (2.0 eq.). 0. l Manila, Labs 0 168.0 15.8 23.7, 7.0 (1.0 0( 8. 7 Rosin-iumario adduct 302.0 50 50 32.2 (0.8 eq.) 7. 0.7 Glycerol-fumarate, rosin-modified 117. 8 50 50 15.6 (1.0 (311). 7. 2 Glycerol-phthalate, rosin-modified 118 50 50 15.7 (1.0 eq.). 8. l

On dilution with water varnishes of Examples 18 and 21 gave milky, soapy solutions while those of Examples 19, 20 and 22 gave slightly cloudy, soapy solutions.

The behavior or these salts in inks is illustrated by the following:

An ink was made using the varnish 0! Example 1, 65 parts, carbon black, 15 parts, and diethylene glycol, 20 parts. The ink had good length and fiow and films on paper dried in approximately one second when exposed to steam. The pigment was very well bound in the dried films and waterresistance was excellent immediately after drying. This speed of attainment of water-resistance in the film varies with the formula of the ink and the type of stock upon which it is printed. In some cases immediate attainment of water-resistance was noted. In others 8 to 48 hours were required before the films became water-resistant.

It will be understood that inks may be prepared from the vehicles described by mixing with various pigments both black and colored according to well known methods of ink formulation.

The term acid number in the claims is the number or milligrams of potassium hydroxide equivalent to 1.0 gram of substance.

Various changes may be made in the details of the ink formulations without departing from the We claim:

1. A vehicle for use in making printing inks consisting essentially of a nonaqueous solution in a liquid polyglycol of a water-miscible salt formed by reacting substantially equimolar proportions of an amine and a resin having an acid number between 60 and 305.

2. A vehicle for use in making printing inks consisting essentially of a nonaqueous solution in a liquid polyglycol of a. water-miscible salt formed by reacting substantially equimolar proportions of triethanolamine and a resin having an acid number between 60 and 305.

3. A vehicle for use in making printing inks consisting essentially 01' a nonaqueous solution in a liquid polyglycol 01 a water-miscible salt formed by reacting substantially equimolar proportions of ethylene diamine and a resin having an acid number between 60 and 305.

4. A vehicle for use in making printing inks consisting essentially of a nonaqueous solution in a liquid poly lycol or a water-miscible salt formed by reacting substantially equimolar proportions of morpholine and a resin having an acid number between 60 and 305.

JOHN w. KROEGER. DANIEL. J..O CONNOR,' JR.- 

